Aim and procedure of Siffre (1975)
Aim: to find whether the sleep-wake cycle is driven by an internal body clock or by external cues like daylight. Procedure: Siffre lived alone underground about six months with no clock, calendar or daylight — every zeitgeber gone. He controlled his own electric light, so he had light but no cue to the time. A surface team logged when he woke, ate and slept but never told him the time; he also tested his dexterity, memory and eyesight.
The findings examiners credit
Wrong results cap an answer at one mark. The cycle LENGTHENED beyond 24 hours — around 26 hours — so he counted far fewer days than had passed. It also became IRREGULAR: cycles reached about 48 hours, and 18 to 52 hours are accepted, so say "lengthened AND varied". His dexterity, memory and eyesight worsened, and his mood was low. Conclusion (not result): an internal clock keeps running with no cues but free-runs past 24 hours and drifts, so light is needed to reset it.
Strengths and weaknesses of Siffre
Justify each point, not just label it. Strengths: every time cue was removed, so the drift shows an internal clock; the surface team logged the times (objective); six months let a small drift show. Weaknesses: one person, so another might free-run to a different length (generalisability); he was researcher AND participant (subjectivity); he controlled his own light (cues not fully removed); the extreme conditions could explain the worse memory and mood (confounding).
Siffre is the evidence, not the explanation
Keep the chain straight. The circadian rhythm (~24 hours) is the thing explained; the pineal gland and melatonin are the internal machinery; light is the zeitgeber that resets it; and Siffre (1975) is the EVIDENCE — remove it for six months and the rhythm keeps going but drifts to ~26 hours, so the clock is internal yet needs the cue. A question naming the study does not want the explanation; one case shows a cycle CAN free-run past 24 hours, not the typical length.
Drawn from real examiner reports.
Wrong findings cap you at one mark
Wrong results cap an answer at one mark, so half-remembered numbers lose marks. The cycle LENGTHENED, not shortened — about 26 hours, later irregular up to about 48 hours, which is a whole wake-plus-sleep CYCLE, not a 48-hour sleep. So he counted FEWER days than had passed, not more. His memory and eyesight WORSENED; he did not lose his memory or go blind.
The cap on wrong results is at June 2023 P2 Q31, with creditworthy lengths at June 2024 P2 Q33 (18 to 52 hours) and June 2023 P2 Q31 ("up to 48-hour").
Correct findings with no scenario score zero
The AO2 dependency at its sharpest: on this study, correct results with no scenario link scored NOTHING. Not application: the character's name, repeating the stem, or lifting a scenario sentence. Application ties each finding to the scenario's detail — unchanging light is her lost cue, so her uneven sleep matches Siffre's lengthening. Write AO2 before AO3.
Correct results with no scenario link scoring zero is recorded at June 2023 P2 Q31; the name is not application at June 2022 P1 Q4b and June 2023 P2 Q25; the stem at June 2024 P2 Q10; lifting at June 2023 P2 Q16.
Bodily rhythm needs "natural"
These are marked strictly. A BODILY RHYTHM is a NATURAL biological cycle that repeats — dropping "natural" or giving only an example scores zero. A CIRCADIAN rhythm lasts about 24 hours; an ULTRADIAN rhythm LESS than 24 hours. A ZEITGEBER is an EXTERNAL cue like light. Swap the two rhythms and Siffre's finding breaks: an under-24-hour cycle could not reach 48 hours.
June 2023 P2 Q28 requires "natural" in a bodily rhythm definition; June 2019 P2 Q30 records ultradian rhythms wrongly given as over 24 hours.
A result is not a conclusion
A result is what was measured; a conclusion is what it shows, and giving a result where a conclusion is asked scores zero. Result: "his cycles reached about 48 hours." Conclusion: "the clock keeps running without daylight but free-runs long, so light is needed to reset it." Test: could it be written from the log alone? If yes, it is a result.
A result restated where a conclusion was asked is recorded at June 2023 P2 Q1f and June 2024 P1 Q5a.
Not total darkness; 48 h is a cycle
Two misreadings of the setup. He was NOT in total darkness — he controlled his own electric light; what was removed was every cue to the TIME OF DAY (daylight, clocks, calendars), not light itself. That doubles as a weakness, since light under his control is not full removal of cues. Second, the ~48 hours was a whole wake-plus-sleep CYCLE, not a 48-hour sleep.
Siffre did not prove a 26-hour clock
Both halves are wrong. "People do not need daylight" — no: the cycle kept running but drifted and became irregular, so light is still needed. "The body clock is 26 hours" — it came from one person controlling his own light, so one case shows a cycle CAN free-run long, not the typical length. Extreme conditions weaken the memory and mood findings, not the cycle drift.
Nov 2021 P2 Q35 records AO3 limited to "Siffre is one person"; creditworthy cycle figures are at June 2024 P2 Q33 and June 2023 P2 Q31.
If the study is named, use the study
If a stem says "Using Siffre (1975)", use the study: six months underground, no clocks or daylight, the cycle lengthening to ~26 hours then varying, and worse memory. If it names bodily rhythms, use 9.1.2 — pineal gland, melatonin, light as a zeitgeber — not the study.
The 9-mark Assess: AO1, AO2, balanced AO3
The 9-mark Assess splits AO1/AO2/AO3; the 7-9 band is missed for thin AO3 and no balance. AO1: procedure and findings. AO2: land each point on scenario detail. AO3: weigh both sides, then conclude it shows THAT a clock exists, not WHAT a typical one does. Prose, not bullets.
Two unique points; justify; improvement
A two-mark describe needs two different findings — safest is one about the cycle and one about him. On a strength or weakness add the consequence, not just the label: one person, so another might free-run to a different length. An improvement is not a weakness.
A named study on the specification. You need its aim, procedure, findings (results and conclusions), strengths and weaknesses — and you must be able to apply it to a scenario.
Bodily rhythm — a natural biological cycle in the body that repeats over a period of time. The word natural must be there.
Circadian rhythm — a natural bodily cycle lasting about twenty-four hours, such as the sleep and wake cycle.
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